Lifting-jack



(No Model.) 2 She'ets-Sheefi 1.

H. R. FERRIS.

LIPTING JACK. A No. 249,235. Patented Nov'.8,1 881,

N, PETERS, Phqto-Limgnphar, Wnhingion. u. c.

2 t e on h ab m flu e h S 2 I Rm m e N fl RF M H (No Model.)

No. 249,235. Patented NOV. 8, 1881.

% INVENTOR I r -ogfi ATTORNEYS" UNITED STATES PATENT OFFICE.

HIRAMB. FERRIS, or CLEVELAND, onto.

.LlFTlNG-JACK.

SPECIFICATION formingpart of Letters Patent No. 249,235, dated November8, 1881 To all whom it may concern:

Be it known that I, HIRAM R. FERRIS, of Cleveland, in the county ofGuyahoga and.

State of Ohio, have invented certain new and useful Improvements inLifting-Jacks; and I do hereby declare the following to be a full,

clear, and exact description of the invention,

My invention relates to lifting-jacks; and

it consists in the peculiar construction of the same, as will behereinafter fully set forth and claimed.

In the drawings, Figure l is a side elevation of my jack. Fig. 2 is avertical cross-section of the head and grasping device of the same.Fig.3 is a view of the head with part removed,

showing the grasping device within said head,

and in a closed position. Fig; 4 is also a view of the head with partremoved, showing the grasping device in an open position, and the devicefor locking said grasping device in said open position. Figs. 5 and 6are sectional views, showing different constructions of the jaws of thegrasping device.

A is a post or standard, which is made hot low for the reception of thelifting-shaft.

B is alifting-shaft, which is constructed to have a vertical movement,and is provided at its top with a suitable bearing-surface, B, and atits lower end with a hooker lug, B which extends out from the side ofthe standard, and isparticularly adapted to be used to raise rails andsuch like low weights. The liftingshaft.

B has formed upon. it a ratchet screw-thread, which is preferablymutilated, as shown in Fig. 1, by having two slots cut through it, saidslots being opposite each other, thus forming two ratchets, O 0, (shownmore clearly in Fig. 2,) one on each side of the shaft B.

D is a head, which surrounds the shaft B. This head D contains thegrasping device for raising the shaft B, said grasping device being coiiposed of two jaws, E and E, which act as pawls and engage with thescrew-thread or ratchets O C. I preferably construct the jaws E and E asshown in Figs. 2, 3, and 4, viz: I provide the upper and lower ends ofthe interior of the head D with inclines a, 12,0, and d,

Application filed September 21, 188i. (No model.)

on which rest the inclines at the-upper and lower ends of the jaws E andE, and thus it will be seen that'the gravity of the jaws E and E willactto draw them toward the shaft B and cause them to engagewith the threador ratchets G O, and that the more the head D is forced upward thetighter will the jaws E and E hug the shaft B. This is also true of theconstruction shown in Figs. 5 and 6, which will be easily understoodfrom the said drawings without any further description.

F is" a nut, which is adapted to turn on the shaft B, and is placedbetween the head D and standard A. The ofiice of this nut is to hold theshaft B-at any desired point by bearing against. the top of the standardA. To the head D are attached toggle arms or links G and G, saidtoggle-arms beingalso connected to the short arm of the lever H. Thelever H is pivoted at f to the standard A.

I is a locking device, which is placed between thejaws E and E, and,being operated by the lever J, acts to lock the jaws E E open and allowthe shaft 13 to pass freely between them.

(See Fig. 4.) Fig.3 shows the position of the locking device I when itis not desired to lock thejaws E and E open. i The operation of mydevice is as follows: The shaft B is held up by means of the nutF,whichrests on the top of the standard A. .The long arm of the lever H islifted, which acts through the links G and G to lower the head D. As thehead D islowering, the teeth on the jaws E and E slide over the ratchetscrew-threadO and G on the shaft B, which causes the said jaws E and Eto open, as shown in Fig. 4, and allows the head D to lower, the shaft Bbeing held in position by means of nut F. When the head D has beenlowered sufficiently theleverH is brought down, which acts to forcethehead D up. Now, as the head D is forced upward, the jaws by theirgravity close in toward the shaft B and engage-with the ratchet-teeth Oand G, and the shaft B is raised as far as the short arm of the lever Hwill raise it. As the shaft B is raised it carries with it the nut F,and this nut F is now run downward until it rests on the top of thestandard A, where it again acts to support the shaft B, while the head Dis again lowered, as above described. This operationis repeated untilthe weight is raised thc-desired distance. To lower a weight theoperation is reversed.

When no weight is on thejack, and it is desired to lower the shaft B,the look I is brought into service, asshown in Fig. 4, and locks thejaws open, when, the shaft B being held upby one hand, thenut F mayberun up by the other, and thus the shaft B may be quickly lowered.

What I claim is 1'. In a lifting-jack, the combination, with alifting-shaft provided with ratchet-teeth on opposite sides thereof, ofgraspingdevices ,located on each side of the lifting-shaft, and adaptedto automatically engage the teeth thereon, an actuating-lever, anddevices connecting the lever and grasping .devires,substantially as setforth.

2. In a lifting-jack, the. combination of. a shaft, B, having ascrew-threadand a supportingvnut, F, with a head, D, said head having agrasping device adapted to engage with the said screw-thread, andbein goperated by means of a lever, B, substantially as shown and described.

3. In a lifting-jack, the head 1), said head having the inclinesa, b, c,and d, and the jaws E and E, said jaws being also provided with inclinesadapted to rest on the inclines a, b, c, and d, substantially as and forthe purpose shown and described.

4. In a lifting-jack, the combination, with a lifting-shaft providedwith teeth on its opposite sides, of two grasping devices locatedon eachside of the lifting-shaft, the locking dcvice I, and lever J,substantially as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

. HIRAM R. FERRIS.

Witnesses:

JNo. ORoWELL, Jr., W. E. DONNELLY.

